Dynamic Range Control (DRC) of audio signals has various applications. Commonly, DRC will reduce the dynamic range of an audio signal by some amount by either making soft parts louder, making loud parts softer, or both. A reduced dynamic range is desirable for playback systems that can only reproduce a small dynamic range while maintaining low distortions, in listening environments with distracting sounds, or in situations where the listener does not want to distract others.
DRC evolved from analog hardware to digital algorithms that mimic the analog behavior. The inherent nonlinear behavior of common DRCs can produce audible distortions that occur as harmonic distortions, pumping (gain changes), and modulations.